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Graft copolymerization of acrylonitrile (AN) onto defatted pineapple leaf fiber (PALF) was studied using a CuSO4 and KIO4 combination as an initiator in an aqueous medium in the temperature range 30–500C. The effects of the concentration of potassium periodate, CuSO4, and monomer on the graft yield were investigated. The effects of time, temperature, amount of some inorganic salts, and organic solvents on the graft yield are also reported. A combination of Cu+2—IO −4 in an aqueous medium with an IO −4 concentration of 0.005 mol L−1 and Cu+2 concentration of 0.002 mol L−1 produced optimum grafting for use of 0.1 g defatted PALF with a fiber‐to‐liquor ratio of 1:50 at 500C for 2 h. However, KIO4 and CuSO4 failed to induce polymerization of AN in the presence of PALF when used separately. FTIR and thermogravimetric analysis of the defatted and AN‐grafted PALF were carried out. Grafting improved the thermal stability of PALF. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3035–3043, 2000

Polypropylene/layered silicate nanocomposites were prepared from base polymer (10 MFI) and octadecylamine modified montmorillonite (1.30P nanomer), melt compounded with and without compatibilizer, i.e., maleic anhydride grafted polypropylene (Epolene-G3015). Physico-mechanical properties of the virgin PP and nanocomposites with different nanomer percentages and compatibilizer loadings were studied and compared. Thermal characteristics of nanocomposites were also compared with those of the virgin polymer. TEM analysis of the nanocomposites was carried out to study the dispersion of nanomer in the resulting hybrids. The nanocomposites showed improved mechanical properties over those of the virgin polymer with a marginal increase in specific gravity. Addition of compatibilizer further enhanced the mechanical properties of nanocomposites because of the compatibilization of the clay and host polymer interface. The uncompatibilized nanocomposites showed an increase in thermal stability and a higher melting point. However, the compatibilized nanocomposites showed delayed crystallization due to the presence of an oligomeric fraction of the added Epolene. Polym. Compos. 25:646-652, 2004.

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